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981.
Denis Gaidashev 《Journal of Mathematical Analysis and Applications》2011,374(2):355-373
We prove existence of solutions (?,λ) of a family of Feigenbaum-like equations
(0.1) 相似文献
982.
The so-called Deslongchamps annulation of deprotonated γ,δ-unsaturated β-ketoesters 15 to 2-(alkoxycarbonyl)cyclohex-2-en-1-ones or similarly activated cyclohex-2-en-1-ones offers a versatile access to various kinds of decalindiones. The scope of Deslongchamps annulations was extended by establishing acceptor-substituted benzoquinone monoketals such as 13 as viable substrates. They gave octalindiones such as 35 with diastereoselectivities ≥ 95:5. 相似文献
983.
Complexation of a large variety of Anils (aniline-imines) with boron(III) precursors provides stable Boranils, some of which have been structurally characterized. Analysis of their optical properties reveals that the fluorescence stems from an intraligand charge transfer (ILCT) state with the best quantum yields reaching 90%. Chemistry on the Boranils allows grafting of photoactive modules acting as energy antennae for borondipyrromethene (Bodipy) and subphtalocyanine (SubPc) fluorophores. 相似文献
984.
Charrier T Durand MJ Jouanneau S Dion M Pernetti M Poncelet D Thouand G 《Analytical and bioanalytical chemistry》2011,400(4):1051-1060
This study describes the construction of inducible bioluminescent strains via genetic engineering along with their characterization
and optimization in the detection of heavy metals. Firstly, a preliminary comparative study enabled us to select a suitable
carbon substrate from pyruvate, glucose, citrate, diluted Luria–Bertani, and acetate. The latter carbon source provided the
best induction ratios for comparison. Results showed that the three constructed inducible strains, Escherichia coli DH1 pBzntlux, pBarslux, and pBcoplux, were usable when conducting a bioassay after a 14-h overnight culture at 30 °C. Utilizing
these sensors gave a range of 12 detected heavy metals including several cross-detections. Detection limits for each metal
were often close to and sometimes lower than the European standards for water pollution. Finally, in order to maintain sensitive
bacteria within the future biosensor-measuring cell, the agarose immobilization matrix was compared to polyvinyl alcohol (PVA).
Agarose was selected because the detection limits of the bioluminescent strains were not affected, in contrast to PVA. Specific
detection and cross-detection ranges determined in this study will form the basis of a multiple metals detection system by
the new multi-channel Lumisens3 biosensor. 相似文献
985.
This paper presents an extension of the standard regression tree method to clustered data. Previous works extending tree methods to accommodate correlated data are mainly based on the multivariate repeated-measures approach. We propose a “mixed effects regression tree” method where the correlated observations are viewed as nested within clusters rather than as vectors of multivariate repeated responses. The proposed method can handle unbalanced clusters, allows observations within clusters to be split, and can incorporate random effects and observation-level covariates. We implemented the proposed method using a standard tree algorithm within the framework of the expectation-maximization (EM) algorithm. The simulation results show that the proposed regression tree method provides substantial improvements over standard trees when the random effects are non negligible. A real data example is used to illustrate the method. 相似文献
986.
We apply the Dirichlet form theory to stochastic differential equations with jumps as extension of Malliavin calculus reasoning. As in the continuous case, this weakens significantly the assumptions on the coefficients of the SDE. Thanks to the flexibility of the Dirichlet forms language, this approach brings also an important simplification which was neither available nor visible previously: an explicit formula giving the carré du champ matrix, i.e., the Malliavin matrix. Following this formula a new procedure appears, called the lent particle method which shortens the computations both theoretically and in concrete examples. In this paper which uses the construction done in Bouleau and Denis (J. Funct. Analysis 257:1144?C1174, 2009) we restrict ourselves to the existence of densities; smoothness will be studied separately. 相似文献
987.
Denis de Carvalho Braga Carmen Roc?oreanu 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(9):3046-3054
The purpose of this work, given a nonlinear control system, is to design a four-parameter family of static state feedback such that the corresponding closed-loop control system exhibits controllable Hopf bifurcations of codimension 1 and 2. More precisely, the scalar law designed by us permits the control of the stability of the equilibrium points and the orientation and stability of the periodic orbits. 相似文献
988.
Jani Keyriläinen Manuel Fernández Alberto Bravin Marja‐Liisa Karjalainen‐Lindsberg Marjut Leidenius Karl von Smitten Mikko Tenhunen Aki Kangasmäki Petri Sipilä Christian Nemoz Pekka Virkkunen Pekka Suortti 《Journal of synchrotron radiation》2011,18(5):689-696
High‐resolution analyser‐based X‐ray imaging computed tomography (HR ABI‐CT) findings on in vitro human breast cancer are compared with histopathology, mammography, computed tomography (CT) and magnetic resonance imaging. The HR ABI‐CT images provided significantly better low‐contrast visibility compared with the standard radiological images. Fine cancer structures indistinguishable and superimposed in mammograms were seen, and could be matched with the histopathological results. The mean glandular dose was less than 1 mGy in mammography and 12–13 mGy in CT and ABI‐CT. The excellent visibility of in vitro breast cancer suggests that HR ABI‐CT may have a valuable role in the future as an adjunct or even alternative to current breast diagnostics, when radiation dose is further decreased, and compact synchrotron radiation sources become available. 相似文献
989.
Larrégola SA Alonso JA Sheptyakov D Algueró M Muñoz A Pomjakushin V Pedregosa JC 《Inorganic chemistry》2011,50(12):5545-5557
The synthesis, crystal structure, and dielectric properties of four novel members of the family of double perovskites Pb(2)LnSbO(6) are described. The room-temperature crystal structures were refined from neutron powder diffraction (NPD) data in the monoclinic C2/c (No. 15) space group. They contain a completely ordered array of alternating LnO(6) and SbO(6) octahedra sharing corners, tilted in antiphase along the three pseudocubic axes, with a a(-)b(-)b(-) tilting scheme, which is very unusual in the crystallochemistry of perovskites. The lead atoms occupy highly asymmetric voids with 8-fold coordination due to the stereoactivity of the Pb(2+) electron lone-pair. Several trends are observed for the entire family of compounds upon heating. The Ln = Lu, Yb, and Er oxides display three successive phase transitions in a narrow temperature range, as shown by differential scanning calorimetry (DSC) data, while the Ln = Ho shows only two transitions. Different crystal structure evolutions have been found from temperature-dependent NPD and DSC, following the space-group sequence C2/c → P2(1)/n → R ?3 → Fm ?3m for Ln = Lu and Yb, the sequence C2/c → unknown → P2(1)/n → Fm ?3m for Ln = Er, and C2/c → P2(1)/n → Fm ?3m for Ln = Ho. The Ln/Sb long-range ordering is preserved across the consecutive phase transitions. Dielectric permittivity measurements indicate the presence of a paraelectric/antiferroelectric transition (associated with the last structural transition), as suggested by the negative Curie temperature from the Curie-Weiss fit of the reciprocal permittivity. 相似文献
990.
In this paper, we re-visit Gibbs' second (unresolved) paradox, namely the constancy of the fine-grained Gibbs entropy for autonomous Hamiltonian systems. We compare and contrast the different roles played by dissipation and entropy both at equilibrium where dissipation is identically zero and away from equilibrium where entropy cannot be defined and seems unnecessary in any case. Away from equilibrium dissipation is a powerful quantity that can always be defined and that appears as the central argument of numerous exact theorems: the fluctuation, relaxation, and dissipation theorems and the newly derived Clausius inequality. 相似文献